1. Field of this Embodiment
The present embodiment relates generally to an assembly for attaching handlebars to the steering mechanism of vehicles that use a handlebar for the purpose of steering; such as but not limited to all-terrain vehicles, motorcycles, snowmobiles, or personal watercraft. More specifically, the current embodiment relates the damping of shock and vibration by a handlebar mounting assembly.
2. Prior Art
The earliest bicycles utilized handlebars mounted directly to the steering mechanism of the vehicle with no means of damping shock or vibration. Soon after these early vehicles were introduced the need for damping the shock and/or vibration before the rider's hands was realized. The most common approach to damping the shock caused by rocks, roots, ruts, potholes, or rough terrain in general, beyond suspending the wheels, was the pivoting of the handlebar's clamp about a fixed pin while using a spring to help dampen impacts. These systems provided insufficient vibration isolation and offered no shock damping along the plane that the force was applied or other beneficial plane, or arc larger than the handlebar clamping assembly itself. Other systems have provided some isolation of vibration but lack the handlebar travel needed to adequately reduce impacts transferred to the rider when rough terrain was encountered. Due to the lack of shock absorption along the axis of rotation of the vehicle's steering, the prior art allows forces, applied for the purpose of steering, to be at least partially absorbed in the handlebar shock absorption mechanism, therefore creating less accurate steering.
A. A. Kellogg U.S. Pat. No. 583,483 teaches of a pivoting handlebar clamp and a compression spring intended to relieve the hands of the rider of a bicycle from the effects of jars and shocks communicated to the handlebar. Similar pivoting bicycle handlebar clamps are disclosed in U.S. Pat. No. 1,060,442 by E. Erickson also by E. K. Kuhn in U.S. Pat. No. 2,324,403 also John R. Arnold in U.S. Pat. No. 5,186,074. Richard Orin Trachinski U.S. PAP Pub. No. US 2005/0066766A1 discloses a similar handle bar mount to Kellogg's for motorcycles, ATV's, and bicycles. These embodiments only provide shock absorption in a rotational manner where the maximum size of the radius of this rotational shock absorption is limited to the physical length of the handlebar clamp mechanism. Most of today's modern handlebars have a rise and compound angles; many riders are very discerning about these angles. A major drawback to this earlier art lies in the rotational absorption of energy about the fixed fulcrum with an extremely limited radius where the energy transmitted as a vehicle's front wheel or wheels contact an obstruction is linear. These linear forces cause a rotation of the handlebars therefore causing the handlebar angles, relative to the vehicle's frame, to change. The changes to the rider preferred handlebar angles may create an uncomfortable or even dangerous situation for the rider. A further drawback to this earlier art is the lack of vibration damping; vibration is a known cause of rider fatigue, this prior art fails to adequately isolate the vibration transmitted through the vehicle's frame to the handlebars and to the rider.
Eivind Clausen and James D. Allsop U.S. Pat. No. 5,511,444 teach of a bicycle handlebar assembly with upper and lower linkage members that are parallel and spaced apart and are pivotally attached at their ends. A damping element is disposed against one of the linkage members for slowing the downward movement of the linkage members. This disclosure allows an arcing motion of the handlebars while the handlebar's angle, relative to the frame, is not greatly altered through this arcing motion. While solving this major drawback of the earlier art, this disclosure in the same way as the before mentioned disclosures, only provides shock absorption in a rotational manner with a radius length that is limited to the physical length of the mechanism and also lacks adequate isolation of the vibration transmitted through the vehicle's frame to the handlebars and to the rider.
Cato Hals, Oslo, Norway U.S. Pat. No. 5,678,457 discloses an adjustable handlebar stem where a built-in shock absorber comprising upper and lower profile arms with 4 pivot points; this allows a pivoting shock absorbing motion as a parallelogram allowing an arcing motion of the handlebars while the bar's angle, relative to the frame, is not greatly altered through the arcing travel. This is very similar to the Eivind Clausen and James D. Allsop disclosure, and similarly only provides shock absorption in a rotational manner with a radius length that is limited to the physical length of the mechanism. Hals' disclosure realizes the same shortcomings as the forces transmitted to the handlebars when a vehicle encounters rough terrain are not in the rotational manner.
Rob William Henricksen U.S. Pat. No. 7,018,126 B2 discloses a Multi-Post Shock Absorber Clamp System. This disclosure, like the dual post shock absorber clamp system that has been widely implemented for many years, offers isolation between the triple clamp (the steering mechanism) and the handlebar by compressing upper and lower urethane conicals between the two components. Denis R. VanDeMortel U.S. Pat. No. 6,953,201 B1 discloses the use of isolation strips to isolate the triple clamps from the handlebars. Henricksen and VanDeMortel's previous art does not teach the use of multiple damping materials to dampen multiple vibration frequencies. Therefore these disclosures will only dampen the frequencies that the chosen material can deaden, and will allow all other frequencies to pass, greatly limiting the vibration damping of these embodiments. Furthermore, Henricksen and VanDeMortel's disclosures do not allow for directional travel for the purpose of absorbing shock. By design these systems must have the isolation materials under high compression to allow the vehicle's handlebars to be turned without the increased handlebar leverage on the isolation material causing the isolation material to compress and cause extremely inaccurate steering, therefore causing the highly compressed isolation material to have greatly limited shock absorbing quality and lack the ability to absorb shock along a preferred axis or plane.
W. A. Keetch U.S. Pat. No. 2,583,947 prior art of a motorcycle handlebar which mounts in the same general direction as the fork where the handlebars of the day which came back toward the rider allowing the handlebars to have a rotational shock absorbing motion without the use of a pivot pin. A major drawback to this earlier art lies in the rotational absorption of energy about a fulcrum with an extremely limited radius where the energy to be absorbed is transmitted linearly as a vehicle's front wheel or wheels contact an obstruction in its path. These linear forces cause a rotation of the handlebars therefore causing the handlebar angles, relative to the vehicle's frame, to change. The changes to the rider preferred handlebar angles may create an uncomfortable or even dangerous situation for the rider.
Guy E. Eckel U.S. Pat. No. 1,211,303 disclose a bicycle attachment where two springs provide shock absorption in a linear direction to a block that holds the handlebar. By using the inner walls of the housing to guide the handlebar block, the offset of the handlebars back toward the rider creates torque between the block and the housing. As the rider's hands pushes or pulls on the handlebar, the handlebar acts like a wrench on the block, twisting the block in the housing rather than allowing the block to slide in the housing. This handlebar block torque causes the sticking of the block in the housing therefore causing the entire handle bar mounting assembly to bend and flex. The stuck block will jump and then re-stick as torque force changes direction due to the rider's hands pushing or pulling on the handlebar. The stick and jump effect of Eckel's embodiment is an undesirable affect to a rider and the reason that devices of this nature are not in use. Furthermore the lack of damping in the upward direction causes an abrupt stop of the bars when the spring force pushes the bars in the upward direction, and lacks isolation of the handlebars to dampen vibration.
Bret Bobrovniczky U.S. Pat. No. 6,988,740 discloses a suspension for bicycle seat and handlebar support between a support post of a bicycle and a suspended member such as a bicycle seat and bicycle handlebars, having an invertible connector body with support post mounting. Bobrovniczky's embodiment, having downwardly extending slide pins that would hinder the steering of a vehicle employing a triple clamp steering component or a steering stem and a post mounting design, renders this embodiment nonfunctional for motorcycles, ATV's, snowmobiles, or other vehicles with the before mentioned steering components. In Bobrovniczky's embodiment, forces applied to the handlebars for the purpose of steering or rough terrain causing rotation about the steering axis, exerts force on the slide pins by the support bracket causing the bending of the levered slide pin. In order to counter this effect extremely large and heavy slide pins must be used adding unwanted weight to the vehicle. Additionally the lack of damping in the upward direction causes an abrupt stop of the bars when the spring force pushes the bars in the upward direction. Furthermore, this embodiment does not provide isolation of the handlebars for the purpose of damping vibration.
There have been attempts to provide shock damping handlebar assemblies to minimize the shock realized by the rider of vehicles that employ handlebar assisted steering. These assemblies have typically comprised a pivoting linkage. A disadvantage to these types of assemblies is that they subject the rider's wrist to a twisting force as the bars pivot about the assembly's fulcrum. The few slidably controlled embodiments lack the ability to be used by vehicle's having a triple clamp or a steering stem, the two most common methods for transferring handlebar assisted steering forces of vehicles other than the conventional bicycle, or the design to allow travel of the handlebar in a predetermined beneficial path. Furthermore, the prior art lacks the vibration isolation of its suspended components, a known cause of rider fatigue.